Hydraulic system for valve in head engines



HYDRAULICSYSTEM FOR VALVE IN HEAD ENGINES INVENTOR. "45 JOHN w. TATTER BY omvfi ATTO EYS FIG.3.

o 7 w 4 5 3 4 p f @I 2 4 Z747 3 J m Fa r H M AA/A/ 2 i M n v w E Q n Y 2 3 w M m :w 3 M Q 4 1 4 //////////////////v///// m w M a %//)//////7 July 17, 1956 United States Patent Ofice 2,754,810 Patented July 17, 1956 HYDRAULIC SYSTEM FOR VALVE IN HEAD ENGINES John W. Tatter, Akrn,'0hio Application August '13, 1952, Serial No. 304,121 Claims. (01. 123-90 My invention relates to engines and more particularly to a valve in head engine and-to a hydraulic system for actuating the engine valves.

An object of the present invention'is to provide animproved engine by constructing a novel hydraulic valve system for a valve in head engine providing for automatic adjustment of the valves equivalent in operation to the present day type of hydraulic tappets, for eliminating rocker arm noise and lubrication for moving parts in the cylinder heads.

Further advantages-of the present construction are that the valves may belocated in any position and-another advantage is that it is possible to obtain-a maximum valve lift with aminimum cam lift and to automatically obtain a progressively increasing valve lift at increasing engine speeds, whereby'to provide for faster and improved scavenging of the exhaust gases and to generally improve engine operation because of generally improved combustion, cooler engine operation permitting the design of highercompression ratios and allaroundoperation.

For a more detailed understanding of my invention reference may be had to the-accompanying'drawing illustrating a preferred embodimentof the invention in which like characters refer to like parts throughout the several views, and in Which:

Fig. l is avertical transverse sectional view through a valve in head internal combustion engine showing the engine valve in open position.

Fig. 2 is anenlarged detail sectional view of the cam actuated piston and cylinder assembly in a retracted position, and

Fig. 3 is a diagrammatic view showing how a plurality of hydraulic valve actuating systems maybe'connected with a source of fluid pressure-supply for application to a multi-cylinder engine.

1 have chosen to illustrate my invention in connection with a valve in head internal combustion engine since a hydraulic valve actuating system such as I have developed is a verypractical application with this type' of engine. It will of-course be quite obvious that the invention can be applied to' engines other than the valve in head type.

Theaccompanying drawing illustrates my invention in detail and the improved and novel-hydraulic valve'actuating system is shown as embodied in a valve in head engine comprising-acrankcase10, cylinder 11, cylinder head 12, a crankshaft 13 supported by the crankcase and a camshaft 14 also-supported by the crankcase and driven in time relationby said crankshaft in the conventional manner.

The engine cylinder block and cylinder head carry the conventional cooling jackets andthe engine cylinder is ported for intake and exhaust in the customary manner. One such port 20 is shown and the valve 21 for same is shown as being supplied by a valve guide 22, the valve stem projecting above the valve guide and connected to a piston 23 operable in the cylinder 24 secured to the cylinder head (see Fig. 1). A valve spring 25 urges the piston 23 outwardly of the cylinder 24 to seat the valve 21 and close said port 20. An inlet port 26 admits fluid under pressure to the cylinder 24 on top of the piston, said inlet port 26 being connected by a conduit or other suitable duct 27 to a cylinder 30 mounted on the crankcase.

A piston or tappet 31 is operable in the cylinder 30 and said piston bears on a cam 32 carried by the cam-shaft 14. As the cam is rotated, it engages the underside of said piston 31 and advances same to build up fluid pressure in cylinder 30 transferring this pressure to cylinder 24 and opening the engine valve 21. As the cam 32 passes from under the piston or tappet 31 is returned or retracted, the spring 33 urging said piston or tappet against the cam, Will reduce the pressure-in the cylinder 24, permitting the valve spring 25 to function and close the engine valve 21.

The engine is provided with a suitable source of fluid pressure, preferably very light oil under pressure in a reservoir 40 preferably supported on the dash 41. This reservoir is provided with a pressure gauge 42 and a filler cap 43 for the purpose of introducing air under pressure preferably at about 15 lbs. over the hydraulic fluid stored in the reservoir or container 40. A line or conduit 44 connects the reservoir 40 with the intake port 45 of the cylinder 30. This intake port 45 is normally open ('see Fig. 2) but same is arranged to be closed by valve 46 during the operating cycle of the valve actuating system.

It will be observed that this valve 46 is provided with a head or enlarged part arranged to engage under the valve guide -47 carried by the piston or tappet 30, the compression spring 34 bearing on the under surface of the valve 46. As the piston or tappet is initially lifted by the cam, the valve 46-is raised and closes off the port 45, the rubber insert 50 seating against the end of the passage 45 cutting oif communication of cylinder 30 with the source of fluid pressure supply, and the remaining advance of the piston or tappet 31 builds up the pressure which is freely and openly transmitted to the cylinder 24 on top of piston 23 to open the engine valve 21.

In the return or retracting stroke of the piston or tappet 31, the pressure in cylinder is first relieved, permitting the engine valve 21 to close and during the very last part of the return stroke, the tappet guide 47 engages the shoulder on the valve 46 and opens the cylinder 34) to the source of fluid pressure supply, the spring 34 under the valve 46, which urges same onto its seat, serving to maintain the valve 46 on its seat until it is positively unseated by the guide 47. The guide carries a groove or passage 48 venting the chamber 49 beneath the valve 46.

Actual operating tests of this mechanism has resulted in obtaining a valve lift greater than the cam lift because of the difierence in diameter of :thepistons 31 and 23. A carn lift of A has resulted in a valve lift of at very slowengine speeds of around 800 R. P. M., the valve lift is about and at engine speeds of around 3500 R. P. M., the valve lift is around W The tube or conduit connecting cylinders 30 and 24 is of course a great deal less in diameter than either of the cylinders, theoil rushing through this conduit at fairly high speed as same is being transferred from one cylinder to the other, this high oil velocity causing added lift of the valve at higher engine speeds.

While I have illustrated but one form of the invention, it Will be apparent to those skilled in the art to which my invention pertains that various changes and modifications may be made without departing from the spirit of the inventionor from the scope of the appended claims.

I claim:

1. A hydraulic valve actuating instrumentalityfor :an internal combustion engine hydraulic valve assembly comprising an impulse pump assembly carried by said engine and operatively driven by said engine, said pump assembly having a pump cylinder, a piston operable in said cylinder and reciprocated therein to actuate the hydraulic valve assembly, a supply conduit directly openly connected with said pump cylinder, a delivery conduit openly connected with said pump cylinder and adapted for connection with said hydraulic valve assembly, and valve means directly carried by said piston and advanced by said piston on its power stroke to close off communication between the pump cylinder and said supply conduit, said valve means yieldingly supported by said piston and having relative longitudinal movement with respect to said piston by which it is supported whereby to permit further advance of the piston to actuate said hydraulic valve of said engine while the aforesaid valve means is closed.

2. A hydraulic valve actuating instrumentality for an internal combustion engine hydraulic valve assembly having a pump chamber and comprising an impulse pump assembly carried by said engine and operatively driven by said engine, said pump assembly having a pump cylinder, a piston operable in said cylinder and reciprocated therein to actuate the hydraulic valve assembly, a supply conduit directly openly connected with said pump cylinder, at delivery conduit openly connected with said pump cylinder and adapted to be connected with said hydraulic valve assembly, and valve means directly carried by said piston and advanced by said piston on its power stroke to close on communication between the pump cylinder and said supply conduit, said valve means yieldingly supported by said piston and having relative longitudinal movement with respect to said piston by which it is supported whereby to permit further advance of the piston to actuate said hydraulic valve of said engine while the aforesaid valve means is closed, and motion multiplying means interposed between said impulse pump assembly and said hydraulic valve assembly comprising a pump cylinder of the impulse pump assembly having an effective diameter which is different than the diameter of the pump chamber of said hydraulic valve assembly.

3. A hydraulic valve actuating instrumentality for an internal combustion engine hydraulic valve assembly comprising an impulse pump assembly carried by said engine and operatively driven by said engine, said pump assembly having a pump cylinder, a piston operable in said cylinder and reciprocated therein to actuate the hydraulic valve assembly, a supply conduit directly openly connected with said pump cylinder, a delivery conduit openly connected with said pump cylinder and adapted to be connected with said hydraulic valve assembly, and valve means directly carried by said piston and advanced by said piston on its power stroke to close off communication between the pump cylinder and said supply conduit, said valve means yieldingly supported by said piston and having relative longitudinal movement with respect to said piston by which it is supported whereby to permit further advance of the piston to actuate said hydraulic valve of said engine while the aforesaid valve means is closed, said piston and valve means comprising a unitary assembly, the piston having an axially extending recess, a valve guide secured to the piston, said valve having a shoulder engaged with the underside of said guide and serving to withdraw the valve off its seat when said piston is fully retracted to place said pump cylinder in open communication With the supply conduit, and a spring urging said valve outwardly of the piston, said spring permitting relative movement of said valve and piston on advance of said piston.

4. A hydraulic valve actuating instrumentality for an internal combustion engine hydraulic valve assembly comprising an impulse pump assembly carried by said engine and operatively driven by said engine, said pump assembly having a pump cylinder, a piston operable in said cylinder and reciprocated therein to actuate the hydraulic valve assembly, a supply conduit directly openly connected with said pump cylinder, a delivery conduit openly connected with said pump cylinder and adapted to be connected with said hydraulic valve assembly, and valve means directly carried by said piston and advanced by said piston on its power stroke to close off communication between the pump cylinder and said supply conduit, said valve means yieldingly supported by said piston and having relative longitudinal movement with respect to said piston by which it is supported whereby to permit further advance of the piston to actuate said hydraulic valve of said engine while the aforesaid valve means is closed, said piston and valve means comprising a unitary assembly, the piston having an axially extending recess, a valve guide secured to the piston, said valve having a shoulder engaged with the underside of said guide and serving to withdraw the valve off its seat when said piston is fully retracted to place said pump cylinder in open communication with the supply conduit, and a spring urging said valve outwardly of the piston, said spring permitting relative movement of said valve and piston on advance of said piston, and a compression spring in said pump cylinder and bearing on top said piston to retract the piston and said valve guide carried thereby.

5. A hydraulic valve actuating instrumentality for an internal combustion engine hydraulic valve assembly comprising an impulse pump assembly carried by said engine and operatively driven by said engine, said pump assembly having a pump cylinder, a piston operable in said cylinder and reciprocated therein to actuate the hydraulic valve assembly, a supply conduit directly openly connected with said pump cylinder, a delivery conduit openingly connected with said pump cylinder and adapted to be connected with said hydraulic valve assembly, and valve means directly carried by said piston and advanced by said piston on its power stroke to close off communication piston by which it is supported whereby to permit further advance of the piston to actuate said hydraulic valve of said engine while the aforesaid valve means is closed, said piston and valve means comprising a unitary assembly, the piston having an axially extending recess, a valve guide secured to the piston, said valve having a shoulder engaged with the underside of said guide and serving to withdraw the valve off its seat when said piston is fully retracted to place said pump cylinder in open communication with the supply conduit, and a spring urging said valve outwardly of the piston, said spring permitting relative movement of said valve and piston on advance of said piston, and a compression spring in said pump cylinder and bearing on top said piston to retract the piston and said valve guide carried thereby, said valve means comprising a plunger disposed concentrically with respect to said piston and normally projecting above the face of the piston, said supply conduit opening through a port in axial alignment with said piston and plunger, said plunger end face slightly spaced from said port when the piston is retracted and advanced to close said port by the spring acting thereon on the initial advance of said piston and displacement of the shoulder on said valve with respect to the underside of said valve guide.

References Cited in the file of this patent UNITED STATES PATENTS 1,692,845 Kolb Nov. 27, 1928 1,815,445 Noble July 21, 1931 2,011,864 Lundh Aug. 20, 1935 2,595,775 Wrangell May 6, 1952 FOREIGN PATENTS 527,254 Great Britain Oct. 4, 1940 

